Saturday, March 22, 2008

A couple of days back, someone commented on the post about Zombie Feynman, where I mentioned that folks have compared Optimality Theory in phonology with String Theory in physics. This led me to mention opacity, bringing this question:

How pervasive is opacity really? (I'm not trying to be obnoxious, I really want to know!) I'm still a newbie (i.e. lowly grad student), but every time I hear someone talk about opacity, they mention the same Hebrew examples.

First, if your question doesn’t start with ‘yo, asshole’ or ‘as every schoolboy knows’, I figure it doesn’t count as obnoxious. (And we live by the energy of grad students precisely because they almost always really want to know answers.)

OK, starting with some background for non-linguists. Opacity is a name for patterns that are not 'surface true'. Following Kiparsky's formulation, take this kind of process:

A → B/C__D

That is, some sound 'A' becomes 'B' when it appears between 'C' and 'D'. It's opaque if you do get A in this environment or if you get B for some other reason. This was long captured by using ordered rules. (McCarthy, in his Thematic Guide, aptly says that serial derivation allows us to "state temporary truths".) Here are two examples from Greg Iverson's "Rule Ordering", Handbook of Phonological Theory:

First, Canadian Raising for one variety of Canadian English (following Joos 1952) interacts with flapping in a crucial way:

Flapping: /t/ merges with /d/ between vowels to what we can characterize as [d].

If the rules apply in that order, you get rider [raydɚ] but writer [rəydɚ]. Looking only at the surface form, writer looks like it doesn't have the environment for raising but it does. (In some kind of Canadian English, it works the other way.) The 'temporary truth' would be the moment where writer has a /t/ to trigger raising, even though we don't see the /t/ on the surface.

Second, in Icelandic, the word for 'package' is böggli, from /bagg+ul+i/. The /u/ triggers umlaut (/a/ becomes [ö]) but it is then deleted, leaving its 'trace' on the final form. Here, it looks like you don't have the environment for umlaut, but you do.

And opacity is pervasive in human language. Derivations and Constraints in Phonology, ed. by Iggy Roca explores a set of examples from Dutch, Berber, Polish, Yokuts and so on, in addition to the now-famous Hebrew spirantization examples Idsardi treats there.

That answers the reader's direct question, but consider why this matters: In any monostratal theory (one without stages of derivation), getting these interactions is a huge problem. This isn't the place to run through them, but some readers will be familiar with sympathy theory, comparative markedness, and so on. I heard one person sum it up this way a few years ago:

Opacity is ubiquitous in human language, and earlier theories of phonology could deal with it easily. It's hard to see why those advantages have been abandoned for an approach that can't handle opacity without lots of gymnastics, if at all, for benefits that don't look all that great.

Those gymnastics remind some people of String Theory, I think.

Finally, I beg forgiveness for polluting the consistently low level of discussion here with a moment of theoretical linguistic seriousness, but I promise we'll return to the gutter faster than a 16-pound ball hurled by a hyperactive, sugar-high kid at a bowling alley birthday party.

Thanks for the update, and sorry to detract from the normal "intelligent but not too academic" nature of this blog! (btw, I watched Wisconsin win yesterday - thankfully, since I have them going to the final four. Now that Purdue's out of it, I gotta cheer for the Big Ten teams left.)

Hopefully all will forgive me if I add one point to the opacity discussion. It seems that (at least most) opacity is the result of morphological interaction. Many of these cases can be handled by the various OT mechanisms that have been proposed to account for cyclicity in a parallel model.

Another note about opacity (since I have but the vaguest idea of what "March Madness" even is...): various authors have also argued that opacity tends to be the result of accumulated historical residue; see in particular Nathan Sanders's UCSC dissertation.

Yeah, a lot of the problem can be moved to morphology, and that's something I happily accept for a fair number of cases. The kinds of view I was trying to represent in the post and earlier comments reflect positions that can differ on that point, though. A lot of those people seem uncomfortable with at least some of the proposals involving cyclicity in OT.

And almost all of the problem is precisely, as the highly regarded phonological theorist Adam Ussishkin says, the result of building up of historical residues. In some ways, I think, how to incorporate such layers of residues into a synchronic grammar is again getting play as a major issue in theoretical circles -- Evolutionary Phonology hasn't particularly tackled opacity as a big issue that I know of, but its very historical perspective certainly would open that door. (I actually had drafted a whole big thing about this for the post but deleted it as going too far off track. Maybe the next serious post should be about that.)

Go Badgers! (Actually, I'm bummed about the women's hockey team losing the national championship yesterday, but they had an incredible season and they won the last two … .)

Well, the Canadian Raising example you gave in the post remains a hard nut to crack, despite a lot of effort. Bill Idsardi calls such patterns 'allophonic opacity' and he has laid out some arguments here: http://www.ling.umd.edu/~idsardi/work/2005canraising6.pdf

I second that an EP approach to opacity would be an interesting research topic! I don't know of any published research in the area. (Of course, if it's productive, we still have to figure out how to model it synchronically and not just how it got to be that way...)

Haha, Mr. Verb. I actually thought to myself after posting it that "intelligent but not too academic" would be a good description on your sidebar, and there it is! Thanks for making me laugh while I take a break from grading...I guess now I should get back to it.

Well, this blog exists to give people a break from grading. At some level of abstraction, anyway. I was going to get rid of that whole sidebar of quotes, but good ones suddenly started coming in. Go figure.

Anytime, Mr. V. I was hoping to direct some of the way-too-academic (and way-too-something-else) commentary over there to spare you some of the pain, but to no avail. People clearly like your blog better, and for good reason.